Process for preparing stable heating oil



PROCESS FOR PREPARENG STABLE HEATING GIL Richard W. Sauer, Barrington,N.J., and Arthur F. Weed, Wilmington, DeL, assignors to The AtlanticRefining Company, Philadelphia, Pa., a corporation of Pennsylvania NoDrawing. Filed Mar. 28, 1958, Ser. No. 724,508

4 Claims. (Cl. 238-226) This invention relates to a process for theproduction of high quality heating oil blends comprising virgin andcatalytically cracked constituents. The invention is more particularlydirected to a process for the separate pre-treatment of catalyticallycracked heating oil fractions and virgin heating oil fractions wherebythey may be etfectively blended to produce a high quality heating oilproduct which remains stable in storage.

The fuel compositions to which this invention relates are those whichare used primarily in oil burners for heating purposes and are generallycharacterized as heating oils. Heating oils may be derived frompetroleum by various methods, including straight distillation from crudepetroleum oil and catalytic cracking of various petroleum oil fractions.Suitable fractions of virgin and catalytically cracked components may beblended to obtain a heating oil fraction boiling in the range of about350 F. to 675 F. It is known, however, that heating oils consisting inpart of catalytically cracked components tends to be unstable whenstored in contact with air resulting in color degradation and theformation of a deleterious sediment. Moreover, when catalyticallycracked heating oil fractions are blended with virgin heating oils theresulting blend may be substantially poorer in quality than either ofthe components due to their incompatibility. Consequently, the sedimentin the blended oils may cause valves or filters to clog, or otherwisecause the burner systems to mal function.

It is known that catalytically cracked heating oils contain aromaticmercaptans such as thiophenols, thiocresols and thioxylenols'. It isalso known that virgin heating oils contain aliphatic mercaptans. It hasbeen established that aromatic mercaptans play an important role insediment formation and color degradation, but the effect of aliphaticmercaptans has not been established. The exact nature of the sedimentand the mechanism by which it is formed have not been determinedheretofore, although they have been a subject of study for some time.

Various methods have been proposed to preclude sediment formation andcolor degradation in order to attain compatible blends of virgin andcatalytically cracked heating oil stocks. It is standard refinerypractice to treat a blend of virgin and catalytically cracked heatingoil constituents with a dilute caustic alkali solution, for example 5percent NaOl-I, in order to remove mercaptans therefrom. This practiceis ineffective in that only a portion of the aromatic mercaptans areremoved from the blend while none of the aliphatic mercaptans areremoved. Consequently it is usually necessary to use dispersingadditives or sediment inhibitors in order to obtain a stable blend.

It has been proposed to remove mercaptans by hydrogenating the combinedpool of virgin and catalytically cracked stocks. This procedure,however, is costly when applied to the total pool. It has also beenproposed to v tent C treat the catalytically cracked constituentseparately with dilute caustic solution, but this too is ineffective inremoving entirely the aromatic mercaptans from the catalytically crackedcomponent and does not, by itself, render the subsequent blends ofvirgin and catalytically cracked constituents compatible.

Various procedures have been proposed for the separate treatment of thevirgin constituent of heating oils. Caustic treatment of the virginfraction fails to remove aliphatic mercaptans. Sweetening processes, forexample, hypochlorite treating, doctor sweetening and copper treatingare likewise ineflective. Although causticmethanol treatment removesmercaptans from naphtha and gasoline fractions it fails to remove highermolecular Weight mercaptans present in the higher boiling heating oilfraction. Cresolate treating or treatment with sodium salts ofisobutyric acid and caustic serve to increase the solubility of thealiphatic mercaptans in the caustic solvent but, like thecaustic-methanol treatment, do not completely remove the mercaptans.

It is, therefore, an object of this invention to produce compatibleheating oil blends from catalytically cracked and virgin constituentswhich remain stable in storage without sediment formation and withoutcolor degradation.

It is another object of this invention to produce high quality heatingoil blends from catalytically cracked and virgin constituents by anefficient and economic process.

Other objects and advantages will be apparent from a reading of thespecification and the appended claims.

It is now theorized that sediment formation in heating ils containingcatalytically cracked stocks is due to oxidation of heating oilcomponents by oxygen in air, catalyzed by aromatic and aliphatic thiols,and condensation of the oxidized components through ester linkages.Decarboxylation of the sediment by pyrolysis showed the presence of (a)hydrocarbons, such as benzenes, tetralins, naphthalenes, diphenyls, andtr-icyclic aromatics, (b) nitrogen compounds, such as pyrroles, indoles,carbazoles, pyridines, and quinolines, and (c) small amounts of sulfurcompounds, such as thiophenes and cyclic sulfides. The side-chainoxidation of these reactive hydrocarbons, nitrogen and sulfur compoundspresent primarily in the catalytic component is catalyzed by aromaticand aliphatic thiols to form hydroperoxides,

catalyzed CHs-ACH2O 0H by thiols on3-A-'orra+0,

wherein A is a hydrocarbon, nitrogen compound, or sulfur compound of thetype enumerated above. The hydroperoxides condense to form intermediatecomplexes,

This is in agreement with the sediment inhibiting eifect which was foundfor bases in general. When the de- Further oxidation of the initialester side chains results in forming more ester bonds to yield highermolecular weight products which result in sediment formation and oilsoluble color bodies.v

With respect to sediment formation and color "degradationv it is knownthat catalytically cracked distillates are. much less stable than virgindistillates. It was thought, however, that straight run distillatesmerely had a diluting effect on the sediment forming tendency of thecatalytic component in blends of the two distillates. It has now beendiscovered that aliphatic thiols present in the virgin componentactively contribute to instability in blends with catalytically crackeddistillates. In the presence of aromatic thiols and phenols from thecatalytic component, however, the adverse eifect of the aliphatic thiolsis not apparent. When the aromatic thiols and phenols are removed fromthe catalytically cracked component by the process of the instantinvention, the pronounced effect of the aliphatic thiols in the blendedoils is observed. When the virgin component is separately treated by theprocess of the instant invention and the separately treated componentsare blended a stable heating oil blend results.

In accordance with the present invention a catalytically cracked heatingoil fraction is separately treated with a caustic alkali solution havinga concentration of at least 40 weight percent, and preferably from about50 weight percent to about 70 weight percent. Concentrations lower than40 weight percent are ineffective in completely removing the aromaticmercaptans and thus precluding sediment formation and color degradation.Caustic treatment may be performed at ambient temperatures with causticsolutions having concentrations ranging up to the limit of solubility atthese temperatures. If higher concentrations are desired the oil may beprocessed at elevated temperatures The amount of caustic alkali solutionmay range from about 2 volume percent to about 20 volume percent, fromabout 5 volume percent to 15 volume percent being preferred. The termcaustic alkali solution in this invention refers to solutions of sodiumhydroxide or potassium hydroxide.

The virgin heating oil fraction is separately treated to remove thealiphatic mercaptans therefrom. In accordance with the instantinvention, substantially complete removal of aliphatic mercaptans may beaccomplished by extraction with a solution of sodium Z-aminoethoxide, byclay desulfurization or by treatment with hydrogen. Hydrogen treatmentmay be performed by known hydro desulfurization processes, for example,by utilizing a cobalt molybdate-alumi-na type catalyst at an operatingtemperature of 500 F. to 800 F. and preferably at 650 F. to 750 F. and apressure below 1000 p.s.i., preferably between 300 and 800 p.s.i. Thespace velocity may range from 1 to 20 volumes of hydrogen per volume ofcatalyst per hour. The hydrogen to oil ratio may range from 50 to 5000cubic feet of hydrogen per barrel of feed. The catalyst may be preparedby impregnating soluble salts of cobalt and molybdenum on an aluminacarrier, drying and calcining at about 1000 F. The combined oxides ofcobalt and molybdenum may vary from 5 to 20 weight percent and the ratioof cobalt to molybdenum may range from 0.1 to 2. Other known fieldtanks.

methods of hydrogen treatment which utilize other catalysts, for exampleoxides of nickel and tungsten, may be used in the instant invention.Clay desulfurization may also be performed by known processes, forexample, by treatment with a solid adsorbent material such as clay,

. bauxite or fullers earth at 500 F. to 800 F. and preferably at 700 F.to 750 F. and pressures close to atmospheric pressure, preferably from50 to 100 psi. Aliphatic mercaptans may also be extracted from thevirgin heating oil fraction with a solution of sodium 2-aminoethoxide inZ-amindethanol and 1,2-diaminoethane. The sodium Z-aminoethoxide mayrange in concentration from about 4 to about 20 weight percent in thecombined solvents. Higher concentrations result in viscous solutionswith a consequent increase in loss of the treating solu tion. The ratioof 2-aminoethanol to 1,2-diaminoethane may vary from about 1:1 to 1:3.The virgin fraction is treated with about 2 to 20 volume percent of thesodium 2-aminoethoxide solution, about 5 to 15 volume percent beingpreferred. After separation of the phases the oil is water washed toremove any residual solvent.

The separately treated virgin and catalytically cracked constituents arethen blended. Although the blends normally vary from 30 to 70 volumepercent of the catalytically cracked constituent to 70 to 30 volumepercent of the virgin constituent, the two constituents may be blendedin any proportion.

The instant invention may be more fully understood by reference to thefollowing examples which are not intended to limit the inventionthereto.

EXAMPLE I Two types of stability tests were run in. the examples whichfollow. One was an accelerated 24 hour test run with a one liter sampleat 212 F. in an atmosphere of oxygen. In the other test, 0.8 liters ofoil was stored for one year at F. in an atmosphere of air to simulateambient storage in the field. Both tests were run in the dark in glassbottles containing iron strips to give an oil volume to metal surfaceratio typical of that found in At the end of the storage periodsuspended material and lacquer deposited on the metal and glass surfaceswere measured and reported as sediment. The color of the oil was alsomeasured after test.

Gas oil fractions having a boiling range of 650 F. to 1000 F. werecatalytically cracked in a fluidized catalyst process with a commercialsilica-alumina cracking catalyst consisting of about 87 weight percentsilica and 13 weight percent alumina to give a heating oil fractionboiling in the range of 375 F. to 635 F. An accelerated 24 hourstability test was run on various samples of the untreated crackeddistillates in the manner previously described. An ASTM color test wasalso run on these samples. Other samples of the cracked distillates weretreated with 10 volume percent of a 50 weight percent sodium hydroxidesolution at room temperature. One sample was treated with 10 volumepercent of a 50 weight percent potassium hydroxide solution at roomtemperature. An accelerated stability test and ASTM color test were alsorun on these samples. The results are set out in Table I.

In a separate experiment, an untreated sample of a catalytically crackedheating oil was stored for one year at 85 F. as described heretofore.Another sample of the same distillate was treated with 10 volume percentof 50 weight percent sodium hydroxide at room temperature. To a thirdsample of the same distillate, treated similarly with sodium hydroxide,there was added 5.2 mg. of

sulfur as p-toluene thiol per ml. of oil. The three ,samples were storedfor one year at 85 F. The amount moved by treatment with strong causticsolution to yield a relatively stable distillate. The addition of 5.2mg.

Table I EFFECT OF EXTRACTION \VITH 50% CAUSTIC ON THE STABILITY OFCATALYTICALLY CRACKED DISTIL LATES212 F.

Raw 60% Caustic Wash ASTM ASTM Sample Sediment Color Sample SedimentColor (mg/1.) After (mg/1.) After Test Test 76 5% B 6 236+ 74 6+ C 4 2%128 6- D 9 2% 86 5+ E 7 2% 112 7+ F 9 2%+ 142 4% G 8 2% 76 6 H 6 2% 1755% I 6 2 A 127 5% J 7 2 A 118 6% K 6 2 146 6 L 8 2% 106 6% M 7 2%4-1-151 5% N 7 2% 88 6-- 7 2% 119 P 6 121+ 98 4% Q 4 1 /2 84 5+ R 6 2%+ 106S 3 Treated with 10 volume percent of 60 weight percent KOH.

Table 11 EFFECT OF EXTRACTION WITH 50% CAUSTIC ON THE STABILITY OFCATALYTICALLY CRACKED DISTIL- LATES-1 YR. STORAGE AT 85 F.

ASTM Color After Test Sample Sediment Raw 50% Caustic Wash 50% CausticWash plus 5.2 mg. S/lOO ml. as

p-Toluene Thiol EXAMPLE II of the catalytically cracked distillates and65 volume percent of the virgin distillates. Accelerated stability testsTable III STABILITY OF BLENDS OF CATALYTIOALLY CRACKED AND STRAIGHT RUNDISTILLATES AT 212 F.

Raw Blend 5% Caustic Washed Blend Crude Source Straight Run ComponentASTM ASTM Sediment Color Sediment Color (mg/l.) Alter (mg/1.) After TestTest West Texas Ellenberger 106 3% 89 3% Barbers Hill" 45 3% 3?. 2%SanJoaquin 9 2 5 1% Junta Ad0be 1O 2 6 1% Iraq 23 2% 20 2% Kuwait--- 81% 10 2 0ficino 12 West Texas Devonian 53 West TexasPermian. 15 Ruiz 22and ASTM color tests were run on the raw blends. Several samples of thesame blends were treated with 10 volume percent of 5 weight percentsodium hydroxide solutions at room temperature. Accelerated stabilitytests and ASTM color tests were also run on the caustic treated blends.The results are set out in Table III.

The results indicate the instability of untreated raw blends. Comparisonwith Table I makes it appear that the straight run component merely hasa diluting effect on the sediment. Caustic treatment of the blends doesnot appreciably improve their stability.

EXAMPLE III Untreated samples of catalytically cracked and virgindistillates were blended. The blends contained 35 weight percent of thecatalytic distillates and weight percent of the virgin distillates.Varying amounts of aromatic or aliphatic thiols, or both, were added tothe samples. Accelerated stability tests and ASTM color tests were runon the samples containing the added thiols as well as on a samplecontaining no added thiols. The results are set out in Table IV.

Table IV EFFECT OF THIOLS ON THE STABILITY OF A RAW BLEND OFCATALYTICALLY CRACKED AND STRAIGHT RUN DISTILLAIES AI 212 F.

Ooncentra- ASTM Sample Thiol Added tion Thiol Sediment Color Added (mg.(mg/1.) After 5/100 ml.) Test 1- 0.000 14. 4 2 2. 0.77 11.7 2% a- 6. 0s4. 5 3% 4. 7. 7 95. 4 3 5. p-toluene thiol 40. 0 283 6 6....pentanethiol-1- 6.0 17.0 2 7.--. pentanethiol-1 40.0 12.5 2 8. a-toluenethiol 6.0 10. 5 1%+ 9- a-toluene thiol- 40. 0 8. 2 1%+ l0 6. 0 l5. 2 211 23. 6 2%+ 12 peltiane 03:11-11" 40. 0 i 0 p- 0 none io 6.0 13{or-toluene tgiol 40. e 0

po uene t io 6.0 14 {tert-nonyl thiol 37.0 48 5 These data indicate thatthe addition of aromatic thiols markedly degraded the stability of theblends while the addition of aliphatic thiols had relatively littleeffect. A comparison of samples 3, 12, 13 and 14 shows that aliphaticthiols actually appeared to have a slight inhibiting eifect in blendscontaining added aromatic thiols.

EXAMPLE IV Samples of a catalytically cracked component of the typedescribed in Example I were treated with 10 volume percent of a 50weight percent sodium hydroxide solution at room temperature. Thetreated samples were blended with varying amounts of untreated straightrun distill-ates from different crude sources. The aliphatic thiolcontent of the straight run distillates were determined. Acceleratedstability tests and ASTM color tests were run on the blends. The resultsare set out in Table V.

The results indicate that although aromatic thiols are removed from thecatalytically cracked distillates by treatment with strong causticsolution, when the catalytically cracked distillates are blended withuntreated straight run distillates stable blends do not necessarilyresult. The straight run distillates giving poor blending stability werethose with a high aliphatic thiol content. These data, when compared tothe data in Table I, prove that the straight run component has apronounced detrimental effect rather than a mere diluting eitect inblends from which aromatic thiols have been removed.

.AROMATIC THIOLS FROM CATALYTIC COD/IPONENT WITH 50% CAUSTIC StraightRun Component Vol. Sedi- ASTM Percent ment Color Aliphatic St. Run(mg/1.) After Crude Source Thiol in Blend Test Content (mg. S; 100 ml.

37 31 95 37 so 78 4% 37 65 68 3% 37 85 37 2+ 60 50 57 1%+ 60 65 48 3% 6085 20 3% 11 35 38 3 11 50 37 2% 11 65 6 1% 11 80 4 1% 1. 4 36 13 2% 1. 450 13 2M?!- 1. 4 65 13 2y.+ 1. 4 80 12 2 0. 4 65 8 254 0. 5 65 6 1% 0. 855 8 1% EXAMPLE V per volume of feed per hour. Aliphatic thiols'wereremoved from other samples of virgin distillates by extraction with 5volume per cent of an 1132 weight percent solution of sodiumZ-aminoethoxide in Z aminoethanol and 1,2-diaminoethane. The sodiumZ-aminoethoxide solution contained 117 g. sodium Q-aminoethoxide, 308 g.Z-aminoethanol and 617 g. 1,2-diaminoethane. Y

The separately treated heating oil constituents were blended in varyingamounts. Accelerated stability tests and ASTM color tests were run onthe blends. The results are set out in Table VI.

Table VI EFFECT ON BLEND STABILITY AT 212 F. OF REMOVING AROMAIIC THIOLSFROM THE CATALYTIC COMPO- NENT AND ALIPHATIC THIOLS FROM THE STRAIGHTRUN COMPONENT Straight Run Component 1 Cata- ASTM lytlc 1 Sedi- ColorCompo Vol. ment After nent Crude Source Percent (mg. per Test in Blend1.)

West Texas Ellenberger (1). 60 8 1% West Texas Ellenberger (1). 65 6 2-West Texas Ellenberger (1). 65 7 154+ West Texas Ellcnberger (2g. 60 51% West Texas Ellenberger (2 60 5 1% West Texas Ellenberger (3). 65 7 1%West Texas Ellenberger (4). 65 9 Its-\- raq 65 7 1 /4+ Barbers Hill 65 71% West Texas Devonian. 65 9 1% Barbers Hill L- 50 5 192+ Barbers Hill50 4 1r2+ 1 Letters and numbers signify difierent samples of thecatalytic and straight run distillates respectively.

- I Aliphatic thiols removed by treatment with hydrogen. Aliphaticthiols removed from all other straight run samples by extraction withsodium 2-am1noethoxide Solution,

These data prove that separate treatment of the cata lytically crackedand virgin components in accordance with the process of theinstantinvention results in stable heating oil blends.

' EXAMPLE VI A sample of an untreated catalytically cracked distillate,obtained in the manner described in Example I, was blended with a sampleof an untreated virgin distiflate. Another blend was made with twosimilar samples and this blend was treated with 10 volume percent of a 5weight percent sodium hydroxide solution. A third sample of thecatalytically cracked distillate was treated with 10 volume percent of aweight percent sodium hydroxide solution and blended with a sample ofvirgin distillate which had been pre-treated with 10 volume percent of a5 weight percent sodium hydroxide solution. A fourth sample of thecracked distillate was treated with 10 volume percent of a 50 weightpercent NaOH solution and blended with a sample of virgin distillatepreviously treated with 5 volume percent of a solution of sodiumZ-aminoethoxide prepared as in Example V. All blends consisted of 40volume percent of the cracked distillate and volume percent of thevirgin distillate. The blends were stored at 85 F. for 12 months asdescribed heretofore. The aromatic and aliphatic thiol content of eachblend, the amount of sediment formed, and the ASTM colors are set out inTable VII.

I Table VII Samples 1 and 2 demonstrate the instability of a blend 0 ofuntreated heating oil constituents as well as the ineffectiveness ofcaustic treating the blend. Sample 3 indicates the ineffectiveness oftreating the virgin constituent with a weak caustic solution even thoughthe aromatic 'mercaptans are removed from the cracked constituent withstrong caustic. of the instant invention by a long term stability testof a heating oil blend made by the process of the instant invention.

EXAMPLE VII Samples of a catalytically cracked distillate obtained inthe manner described in Example I were treated with 10 volume percent ofa 50 weight percent solution of sodium hydroxide. Several treatedsamples were blended with untreated samples of virgin distillate. Othertreated samples of cracked distillate were blended with samples ofvirgin distillate from various crude sources previously treated with 10volume percent of 5 weight percent sodium hydroxide solution.Accelerated stability tests and ASTM color tests were run on the blends.The results are set out in Table VIII.

These data show that unstable blends result when raw virgin distillatesare blended with cracked distillates from .which aromatic mercaptaushave been removed by strong Sample 4 demonstrates the utility Table VIIIEFFECT ON BLEND STABILITY AT 212 F. F 50% CAUSTIC TREATMENT OF CATALYTICCOMPONENT AND CAUSTIC TREATMENT OI VIRGIN COMPONENT Virgin Component 5%Caustic Treated Virgin Component Raw Virgin Component Sediment SedimentVol. Plus ASTM Plus ASTM Crude Percent Lacquer Color Lacquer Color(mg/100 (mg/100 ml.) ml.)

Webster 65 64 3l+ 66 3% Barbers HilL. 65 35 3% 24 2% Do 50 34 3% 19 2%West Texas Ellenbergen- 65 19 2% 34 3 West Texas Devonian 65 39 3 39 2/3- EXAMPLE VIII A catalytically cracked distillate, obtained in themanner described in Example I, was blended with Ultrasene, acommercially highly refined kerosene which simulates a virgin distillatebut from which sulfur compounds have been removed. A second sample ofcracked distillate was treated with volume percent of a 50 weightpercent NaOH solution and similarly blended with Ultrasene. A third andfourth sample were prepared in the same manner as sample No. 2. Analpihatic thiol mixture containing equal amounts of dodecanethiol-l andt-octylthiol was added to sample Nos. 3 and 4 so that they contained 10mg. of sulfur/100 ml. of the blend and 40 mg. of sulfur/ 100 ml. of theblend respectively. All blends consisted of equal amounts of crackeddistillate and Ultrasene. The blends were stored for 12 months at 85 F.as heretofore described. The results are set out in Table IX.

Table IX EFFECT OF ALIPHATIC THIOLS ON BLEND STABILITY-12 MO. AT 85 F.

Thiol Content (mg. 8/100 ml.) Sedi- ASTM Sam- 505O Blend Cat. InentColor ple Distillate and Ultra- (mg. After sene Aro- Aliper 1.) 12 mo.

matic phatic 1 Raw Cat. Distillate 0.8 None 21 2%+ plus Ultrasene. 2 50%Caustic 0. 05 None 2 1%.-

Treated Cat. Distillate plus Ultrasene. 3 50% Caustic 0. 05 10 70 3%Treated Cat. Distillate plus Ultrasene plus Aliphatic Thiols. 4 Caustic0. 05 40 106 5% Treated Cat. Distillate plus Ultrasene plus AliphaticThiols.

These results demonstrate the adverse effect of aliphatic thiols onblend stability. Sample 2 shows the improvement in blend stability whenthe aromatic thiols are removed from the cracked distillate. Thedetrimental effect on the blend stability of increasing amounts ofaliphatic thiols are shown by the results obtained with samples 3 and 4.

EXAMPLE IX An untreated sample of catalytically cracked distillate,obtained in the manner described in Example I, was blended with a sampleof a virgin distillate which was previously clay desulfurized by passagethrough clay at 700 F. to 756W". and 50 psi. pressure. A second similarblend was made and the blend was treated with 10 volume percent of a 5weight percent sodium hydroxide solution. A third sample ofcatalytically cracked distillate was treated with 10 volume percent of a50 Weight percent sodium hydroxide solution and blended with a sample ofvirgin distillate which was previously cl-ay desulfurized. A fourthsample of cracked distillate was similarly treated with a 50 weightpercent caustic solution and blended with a sample of virgin distillatepreviously treated with a solution of sodium 2-aminoethoxide asdescribed in Example V. A fifth sample of cracked distillate was treatedwith 50 weight percent sodium hydroxide and blended with a virgindistillate which was previously treated with 5 volume percent of acresolate solution. The cresolate solution was prepared by dissolving 84grams of purified cresols, recovered from a Unisol treatment of naphtha,in 500 ml. of 5 weight percent aqueous sodium hydroxide. All blendsconsisted of equal volumes of cracked distillate and virgin distillate.An accelerated stability test was run on each blend of heating oil. Theresults are set out in Table X.

Table X Sample Treatment Sediment No. (mg/l.)

1 VirgiuClay Desulfurized. CatalyticUn- 46.6

treated. Virgin-Clay Desulfurized. Total Blend 16.3

Treated With 5% Caustic. 3 VirginClay Desulfurized. Catalytic- 6.2

Treated with 50% Caustic. 4 VirginTreated with Sodium Aminoethox- 3.8ide. Catalytic-Treated with 50% Caustic. 5 Virgin-Cresclate Treated.Catalytic- 31.3

Treated with 50% Caustic.

These data demonstrate the advantage of separately treating the heatingoil components to remove completely the aromatic and aliphatic thiolsaccording to the process of the instant invention compared to treatmentof the total blend, treatment of the virgin constitutent only, andcresolate treatment of a virgin distillate combined with caustictreatment of a catalytically cracked distillate.

We claim:

1. A process for the preparation of a stable heating oil blend from acatalytically cracked heating oil fraction and a virgin heating oilfraction which comprises separately treatingthe catalytically crackedfraction to remove aromatic mercaptans therefrom by contacting saidfraction with from about 2 to about 20 volume percent of an aqueouscaustic alkali solution :having a concentration of at least 40 weightpercent, separately treating the virgin fraction to remove aliphaticmercaptans therefrom by contacting said virgin fraction with from about2 to about 20 volume percent of a solution of sodium Z-aminoethoxide inZ-aminoethanol and 1,2-diaminoethane having a concentration of fromabout 4 to about 20 weight percent in the combined solvents, the ratioof 2-aminoethano1 to 1,2-diaminoethane ranging from about 1:1 to about1:3, separating the oil and aqueous phases, water washing the oil phaseand blending the treated cracked and virgin fractions.

2. A process for the preparation of a stable heating oil blend from acatalytically cracked heating oil fraction and a virgin heating oilfraction which comprises separately treating the catalytically crackedfraction to remove aromatic mercaptans therefrom by contacting saidfraction with from about 5 to about 15 volume percent of an aqueouscaustic alkali solution having a concentration of from about 50 to about70 weight percent, separately treating the virgin fraction to removealiphatic mercaptans therefrom by contacting said virgin fraction withfrom about 5 to about 15 volume percent of a solution of sodium2-aminoethoxide in Z-aminoethanol and 1,2-diaminoethane having aconcentration of from about 4 to about 20 weight percent in the combinedsolvents, the ratio of 2-aminoethanol to 1,2-diaminoethane ranging fromabout 1:1 to about 1:3, separating the oil and aqueous phases, waterwashing the oil phase and blending the treated cracked and virginfractions.

1 l 1 2 3. The process according to claim 2 wherein the caustic1,805,444 Wilson May 12, 1931 alkali is sodium hydroxide. 1,902,221 DayMar. 21, 1933 4. The process according to claim 2 wherein the caus-2,287,118 Mottalu June 23, 1942 tic alkali is potassium hydroxide.2,525,153 McClennan et a1 Oct. 10, 1950 5 2,592,383 Blatz Apr. 8, 1952References Cited in the file of this patent 82,22; glli el:1 1- -SA 1g-31, 1954 2, 'car s et a. ept. 13, 1955 UNITED STATES PATENTS 2,717,857Bronson et a1. Sept. 13, 1955 1,784,262 Wheeler et a1. Dec. 9, 19302,719,105 Peterson et a1. Sept. 27, 1955 UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION Patent Nos 2,951 o33 A ust so, 1960 Richard WeSauer et ale 7 It is hereby certified that error appears in the printedspecification of the above numbered patent requiring correction and thatthe said Letters Patent should read as corrected below.

Column 1-, line 34L for "tends" read tend column" 9, line 23, for"commercially" read commerclal oolnmn 1O. line 25 Table X, third columnthereof, under the heading "Sediment (mg/l,)"- line 1 for "4606 read4566 line 3:6 for "constitutent read constituent "s Signed and sealedthis 4th day of April 1961,

(SEAL) Atte ERNEST W. SWIDER XkXPQQX ARTHUR w. CROCKER Attesting OfficerActing Commissioner of Patents

1. A PROCESS FOR THE PREPARATION OF A STABLE HEATING OIL BLEND FROM ACATALYTICALLY CRACKED HEATING OIL FRACTION AND A VIRGIN HEATING OILFRACTION WHICH COMPRISES SEPARATELY TREATING THE CATALYTICALLY CRACKEDFRACTION TO REMOVE AROMATIC MERCAPTANS THEREFROM BY CONTACTING SAIDFRACTION WITH FROM ABOUT 2 TO ABOUT 20 VOLUME PERCENT OF AN AQUEOUSCAUSTIC ALKALI SOLUTION HAVING A CONCENTRATION OF AT LEAST 40 WEIGHTPERCENT, SEPARATELY TREATING THE VIRIN FRACTION TO REMOVE ALIPHATICMERCAPTANS THEREFROM BY CONTACTING SAID VIRGIN FRACTION WITH FROM ABOUT2 TO ABOUT 20 VOLUMEN PERCENT OF A SOLUTION OF SODIUM 2-AMINOETHOXIDE IN2-AMINOETHANOL AND 1,2-DIAMINOETHANE HAVING A CONCENTRATION OF FROMABOUT 4 TO ABOUT 20 WEIGHT PERCENT IN THE COMBINED SOLVENTS, THE RATIO2-AMINOETHANOL TO 1,2-DIAMINOETHANE RANGING FROM ABOUT 1:1 TO ABOUT 1:3,SEPARATING THE OIL AND AQUEOUS PHASES, WATER WASHING THE OIL PHASE ANDBLENDING THE TREATED CRACKED AND VIRGIN FRACTION.